// global flag
var isIE = false;

// global request and XML document objects
var req;

// retrieve XML document (reusable generic function);
// parameter is URL string (relative or complete) to
// an .xml file whose Content-Type is a valid XML
// type, such as text/xml; XML source must be from
// same domain as HTML file
function loadCal() {
    var url = "cal/getCal.php";
    // branch for native XMLHttpRequest object
    if (window.XMLHttpRequest) {
        req = new XMLHttpRequest();
        req.onreadystatechange = processReqChange;
        req.open("GET", url, true);
        req.send(null);
    // branch for IE/Windows ActiveX version
    } else if (window.ActiveXObject) {
        isIE = true;
        req = new ActiveXObject("Microsoft.XMLHTTP");
        if (req) {
            req.onreadystatechange = processReqChange;
            req.open("GET", url, true);
            req.send();
        }
    }
}

// handle onreadystatechange event of req object
function processReqChange() {
    // only if req shows "loaded"
    var div;
    div = document.getElementById("calendar");
    if (req.readyState == 4) {
        // only if "OK"
        if (req.status == 200) {
            div.innerHTML = "";
            div.innerHTML = req.responseText;
         } else {
            div.innerHTML = "";
            div.innerHTML = "The ACC District College-Wide Calendar is currently ungergoing maintenance. ";
         }
    }
}